Volatile Byproducts of Carotenoid Degradation as Biomarkers of Maize Infestation by the Maize Weevil () (Motsch.).

Maize () is a major global food crop and a source of industrial raw materials. Effective postharvest storage is important for national food security programs, international trade, and global agriculture economics. The maize weevil () is a primary postharvest insect pest that infests maize during storage and leads to significant losses.

Evaluating the use of in-season measures of pest abundance to predict end-of-season damage: a study in commercial almond (Prunus dulcis).

Background: Pre-harvest pest management tools are essential to minimizing crop loss. The development of predictive models using early warning signs of pest abundance to predict imminent crop loss can guide management decisions and enable targeted, well-calibrated intervention. With sufficient data, in-season measures of pest abundance can be an important factor in generating accurate predictions of damage.

Maize terpene synthase 1 impacts insect behavior via the production of monoterpene volatiles β-myrcene and linalool.

Plant-derived volatiles are important mediators of plant-insect interactions as they can provide cues for host location and quality, or act as direct or indirect defense molecules. The volatiles produced by Zea mays (maize) include a range of terpenes, likely produced by several of the terpene synthases (TPS) present in maize. Determining the roles of specific terpene volatiles and individual TPSs in maize-insect interactions is challenging due to the promiscuous nature of TPSs in vitro and their potential for functional redundancy.

Blueberries infected with the fungal pathogen Colletotrichum fioriniae release odors that repel Drosophila suzukii.

Background: Spotted-wing drosophila, Drosophila suzukii, is a serious pest of thin-skinned fruits. Alternative methods to control this pest are needed to reduce insecticide use, including new repellents. Previous research demonstrated that D.

Field evaluation of glutathione and glutamic acid as host marking pheromones for control of Tephritid fruit flies in a mango orchard in Kenya.

Background: Tephritid fruit flies are a major constraint to the global production of horticultural crops. In Africa, an array of native and alien invasive fruit fly species represents a key challenge to the horticultural industry. In an effort to develop a safer management tool for these pests, we previously identified glutathione (GSH) and glutamic acid (GA), as the host marking pheromones (HMPs) of Ceratitis cosyra and Ceratitis rosa, respectively.

Chemo-Ecological Insights into the Use of the Non-Host Plant Vegetable Black-Jack to Protect Two Susceptible Solanaceous Crops from Root-Knot Nematode Parasitism.

Plant parasitic nematodes (PPNs) develop through three major stages in their life cycle: hatching, infection, and reproduction. Interruption of any of these stages can affect their growth and survival. We used screenhouse pot experiments, laboratory hatching and mortality assays, and chemical analysis to test the hypothesis that the non-host Asteraceae plant vegetable black-jack () suppresses infection of the PPN in two susceptible Solanaceae host plants, tomato () and black nightshade ().

Identification of Repellents from Four Non-Host Asteraceae Plants for the Root Knot Nematode, .

Olfactory cues guide plant parasitic nematodes (PPNs) to their host plants. We tested the hypothesis that non-host plant root volatiles repel PPNs. To achieve this, we compared the olfactory responses of infective juveniles (J2s) of the PPN to four non-host Asteraceae plants, namely, black-jack (), pyrethrum (), marigold (), and sweet wormwood (), traditionally used in sub-Saharan Africa for the management of PPNs.

Sampling of Volatiles in Closed Systems: A Controlled Comparison of Three Solventless Volatile Collection Methods.

Complex inter-organismal communication among plants, insects, and microbes in natural and agricultural ecological systems is typically governed by emitted and perceived semiochemicals. To understand and ultimately utilize the role of volatile semiochemicals in these interactions, headspace volatiles are routinely collected and analyzed. Numerous collection systems are available (e.

Zea mays Volatiles that Influence Oviposition and Feeding Behaviors of Spodoptera frugiperda.

Fall armyworm (Spodoptera frugiperda) is a major global pest of many crops, including maize (Zea mays). This insect is known to use host plant-derived volatile organic compounds to locate suitable hosts during both its adult and larval stages, yet the function of individual compounds remains mostly enigmatic. In this study, we use a combination of volatile profiling, electrophysiological assays, pair-wise choice behavioral assays, and chemical supplementation treatments to identify and assess specific compounds from maize that influence S.

Pollen and yeast change nectar aroma and nutritional content alone and together, but honey bee foraging reflects only the avoidance of yeast.

Floral nectar often contains pollen and microorganisms, which may change nectar's chemical composition, and in turn impact pollinator affinity. However, their individual and combined effects remain understudied. Here, we examined the impacts of the nectar specialist yeast, Metschnikowia reukaufii, and the addition of sunflower (Hellianthus annus) pollen.

Compounds Associated with Infection by the Root-Knot Nematode, , Influence the Ability of Infective Juveniles to Recognize Host Plants.

Plant root chemistry is altered by the parasitism of plant-parasitic nematodes (PPN). Here, we investigated the influence of the infective stage juveniles (J2) of in inducing tomato () root volatiles and chemotactic effect on conspecifics. In olfactometer assays, J2 avoided the roots of 2-day infected plants but preferred 7-day-infected tomato compared to healthy plants.

Microbial Co-Occurrence in Floral Nectar Affects Metabolites and Attractiveness to a Generalist Pollinator.

Microbial metabolism can shape cues important for animal attraction in service-resource mutualisms. Resources are frequently colonized by microbial communities, but experimental assessment of animal-microbial interactions often focus on microbial monocultures. Such an approach likely fails to predict effects of microbial assemblages, as microbe-microbe interactions may affect in a non-additive manner microbial metabolism and resulting chemosensory cues.

Traps and Attractants for Monitoring Navel Orangeworm (Lepidoptera: Pyralidae) in the Presence of Mating Disruption.

The use of aerosol mating disruption for management of the navel orangeworm Amyelois transitella (Walker) in California tree nuts has increased markedly. This treatment suppresses pheromone monitoring traps in neighboring orchards as well as in the orchard under treatment. The current study, therefore, addresses the interrelated topics of which attractant is most effective, how the number of adults captured is affected by trap design, and what sex is captured.

Microbial metabolites elicit distinct olfactory and gustatory preferences in bumblebees.

Animals such as bumblebees use chemosensory cues to both locate and evaluate essential resources. Increasingly, it is recognized that microbes can alter the quality of foraged resources and produce metabolites that may act as foraging cues. The distinct nature of these chemosensory cues however and their use in animal foraging remain poorly understood.

Elicitation of Differential Responses in the Root-Knot Nematode Meloidogyne incognita to Tomato Root Exudate Cytokinin, Flavonoids, and Alkaloids.

Root exudates of plants mediate interactions with a variety of organisms in the rhizosphere, including root-knot nematodes (RKNs, Meloidogyne spp.) We investigated the responses of the motile stage second-stage juveniles (J2s) of Meloidogyne incognita to non-volatile components identified in the root exudate of tomato. Using stylet thrusting, chemotaxis assays, and chemical analysis, we identified specific metabolites in the root exudate that attract and repel J2s.

Identification of Glutamic Acid as a Host Marking Pheromone of the African Fruit Fly Species Ceratitis rosa (Diptera: Tephritidae).

Host marking pheromones (HMPs) deposited by female fruit flies deter other females from overexploiting the same fruit for egg laying. Using a bioassay-guided approach, we identified the HMP of the Natal fruit fly species Ceratitis rosa as glutamic acid, 1, from the aqueous fecal matter extract of ovipositing females by liquid chromatography-quadrupole time-of-flight-mass spectrometry (LC-QTOF-MS). Dual choice oviposition assays showed that both the fecal matter extract and 1 significantly reduced oviposition responses in conspecific females of C.

Cucumber and Tomato Volatiles: Influence on Attraction in the Melon Fly Zeugodacus cucurbitate (Diptera: Tephritidae).

The main hosts of the melon fly Zeugodacus cucurbitate are cultivated and wild cucurbitaceous plants. In eastern Africa, the melon fly is a major pest of the Solanaceae plant Solanum lycopersicum (tomato). We hypothesized that shared species-specific volatiles may play a role in host attraction.

Identification of Key Root Volatiles Signaling Preference of Tomato over Spinach by the Root Knot Nematode Meloidogyne incognita.

The root knot nematode, Meloidogyne incognita (Kofoid and White) Chitwood, is a serious pest of tomato ( Solanum lycopersicum) and spinach ( Spinacea oleracea) in sub-Saharan Africa. In East Africa these two crops are economically important and are commonly intercropped by smallholder farmers. The role of host plant volatiles in M.

Interactions Among Plants, Insects, and Microbes: Elucidation of Inter-Organismal Chemical Communications in Agricultural Ecology.

The last 2 decades have witnessed a sustained increase in the study of plant-emitted volatiles and their role in plant-insect, plant-microbe, and plant-plant interactions. While each of these binary systems involves complex chemical and biochemical processes between two organisms, the progression of increasing complexity of a ternary system (i.e.

Nectar-inhabiting microorganisms influence nectar volatile composition and attractiveness to a generalist pollinator.

The plant microbiome can influence plant phenotype in diverse ways, yet microbial contribution to plant volatile phenotype remains poorly understood. We examine the presence of fungi and bacteria in the nectar of a coflowering plant community, characterize the volatiles produced by common nectar microbes and examine their influence on pollinator preference. Nectar was sampled for the presence of nectar-inhabiting microbes.

Identification of the Ubiquitous Antioxidant Tripeptide Glutathione as a Fruit Fly Semiochemical.

Many insects mark their oviposition sites with a host marking pheromone (HMP) to deter other females from overexploiting these sites. Previous studies have identified and used HMPs to manage certain fruit fly species; however, few are known for African indigenous fruit flies. The HMP of the African fruit fly, Ceratitis cosyra, was identified as the ubiquitous plant and animal antioxidant tripeptide, glutathione (GSH).